Amazon began referring to the Android derivative as Fire OS with its third iteration of Fire tablets. Unlike previous Fire models, whose operating system was described as "based on" Android, Fire OS 3.0 was described as "compatible with" Android.[citation needed]
Based on Android 5.1 "Lollipop",[11] it added an updated interface. The home screen has a traditional application grid and pages for content types, as opposed to the previous carousel interface. It also introduced On Deck, a function that automatically moves content out of offline storage to maintain storage space for new content; the Word Runner speed reading tool; and screen color filters. Parental controls were enhanced with a new web browser for FreeTime mode featuring a curated selection of content appropriate for children, and an Activity Center for monitoring children's usage.[12][13][14] It removed support for device encryption, which an Amazon spokesperson stated was an enterprise-oriented feature that was underused. In March 2016, after the removal was publicized and criticized in the wake of the FBI–Apple encryption dispute, Amazon announced it would restore the feature in a future patch.[15][16]
Based on Android 7.1.2 "Nougat", its main changes and additions include:[17]
Adoptable storage, allowing users to format and use their SD card as internal storage
Doze/App standby, aiming to improve battery life by forcing devices to sleep when not actively used, adding restrictions to apps that would normally continue to run background processes
FireOS 8 is the latest release of FireOS for 12th-13th generation fire tablets, based on Android 11, information about the release became available via Amazon developer documentation around May 2022.
FireOS 8 incorporates changes from Android 10 and Android 11, such as TLS 1.3 support enabled by default, High Efficiency Image File Format (HEIF) support, Dark mode, One-time permissions, Sharing improvements, Device auto backups (user needs to opt-in to device backups), etc.
Although it is noted in the Amazon developer documentation that some Android 11 features such as File Based Encryption (FBE) are not supported yet.[25]
Around November 2023, a report surfaced of Amazon's plans to migrate away from Android to a custom Linux-based operating system known as "Vega". Apps will be HTML5 based, specifically using React Native. Amazon was reported to be developing the operating system since 2017, and planning to launch TVs running Vega in 2024. It is unclear on whether existing Android-based Fire TV devices will get replaced with Vega.[26][27]
Fire OS does not come with Google mobile services pre-installed; therefore, Amazon cannot use the Android trademarks to market the devices.[3] Users are able to sideload the Google Play store;[28] however, full compatibility is not guaranteed if the app depends on Google services.[29]
Fire OS uses a customized home screen (launcher). As of Fire OS 7.3.2.3, the launcher features three sections:
"For You" shows the weather, recently used apps, Alexa integration, then shows recommended content such as apps, books movies, etc.
"Home" is the section for the icons of all of the apps currently installed on the device, apps on the Home section can be moved around or put into folders, a search bar is also available at the top of the launcher to search though local content on the device or search online using the Bingsearch engine.
"Library" shows purchased items from Amazon services, such as apps, books, movies and TV shows from Prime Video, etc.
The OS features a multi-user system, which allows multiple people to set up and use separate user profiles.[32]
Along with Amazon Kids and Amazon Kids+, a suite of parental controls is included which allows parents to create managed child profiles,[33] set limits and set restrictions for minors.[34][35]
^"Fire OS 6 for Fire Tablets". www.developer.amazon.com. September 13, 2021. Archived from the original on August 22, 2021. Retrieved September 13, 2021.
^These exploits usually depend on certain factors such as: Fire OS version, bootloader/fastboot/recovery version, date the device was released (eg. in the case of hardware exploits because the exploit may be fixed with a new revision), etc.
^Google stopped publicly using dessert names after Android 9 (Pie), but the dessert names are still used internally (at Google and in AOSP).[citation needed]